This invention relates to air conditioning and heating and more particularly to apparatus for converting an air conditioner into a heat pump with a reduction in energy loss and with a minimum of elements and fittings.
Heat pumps for residential heating purposes are relatively low cost systems especially in the southern regions of the nation. Conventional heat pump units however have a multitude of complex components which must be connected together by tubing, fittings etc., the whole tending to raise the initial cost of purchasing and installing such units. Additionally, if it is desired to convert an air conditioner into a heat pump for use during the heat season, the additional required components presently available are such that the cost of conversion becomes impractical. For example, the available reversing valves, check valves, expansion valves etc. that must be purchased and the complexities of installing the units result in costs similar to those of purchasing a heat pump initially. Moreover, the known reversing valves which are of the D-valve type are relatively inefficient since the hot and cold fluids are in adjoining portions and heat losses tend to occur. Furthermore, a large number of lines and fittings are required for their installation and these lines additionally result in heat losses. This is similarly true of the available check valves and expansion valves required. In addition, conventional refrigerant accumulator tanks, which should be used to eliminate liquid refrigerant from being dumped into the compressor at start-up during intermittent operation, are installed in the systems in a similar manner, as are the filters required to protect the system. The fluid lines in almost all cases must be sweat soldered onto the components and this frequently results in metal flakes entering the lines and creating damage to the critical elements, especially to the compressor.